To shorten a shift time from pre-contrast scanning to monitoring scanning in an X-ray computed tomographic apparatus for performing three kinds of scanning, i.e., pre-contrast scanning, monitoring scanning, and post-contrast scanning.SOLUTION: An X-ray computed tomographic apparatus includes: an X-ray generation unit that is arranged in a rotation unit to be rotated in the circumference of a subject and generates an X-ray; an X-ray detection unit that is arranged in the rotation unit and detects an X-ray transmitted through the subject; an imaging plan unit that sets an inspection protocol including pre-contrast scanning, monitoring scanning, and post-contrast scanning, and an imaging condition related to the respective kinds of scanning included in the inspection protocol; and a scanning control unit that controls the X-ray generation unit and the X-ray detection unit so as to allow the respective kinds of scanning included in the inspection protocol to be completed within a time for one respiration of the subject in accordance with the imaging condition.SELECTED DRAWING: Figure 1【課題】造影前スキャン、モニタリングスキャン、及び造影後スキャンの3種のスキャンを実行するX線コンピュータ断層撮影装置における、造影前スキャンからモニタリングスキャンへの移行時間の短縮。【解決手段】X線コンピュータ断層撮影装置は、被検体の周囲を回転する回転部に設けられ、X線を発生するX線発生部と、前記回転部に設けられ、前記被検体を透過したX線を検出するX線検出部と、造影前スキャン、モニタリングスキャン及び造影後スキャンを含む検査プロトコルと、前記検査プロトコルに含まれる各種スキャンに関する撮影条件を設定する撮影計画部と、前記検査プロトコルに含まれる各種スキャンが、前記撮影条件に従って、前記被検体の一呼吸分の時間で完了するように、前記X線発生部と前記X線検出部とを制御するスキャン制御部と、を具備する。【選択図】 図1